Can the point-of-instantiation be delayed until the end of the translation unit?

Question

Consider the following small code fragment:

#include  
    
template 
int test(); 
    
int main() 
{     
    std::cout <&l         


        

Answer 1

Explicitly specializing after the explicit call to the template will fail at compilation.

#include  

template 
int test(T y);


int main() 
{     
    std::cout << test(0) << "\n"; 
}

template 
int test(T y) 
{ 
    return 0; 
}

// POI for test() should be right here      

template<>
int test(int y) 
{ 
    return 2; 
}

Check the compilation error here

Compilation error    time: 0 memory: 0 signal:0
prog.cpp:21:15: error: specialization of ‘int test(T) [with T = int]’ after instantiation
int test(int y)